The limitations of existing CALL software [Self, J. (1985) Microcomputers in Education. Harvester Press] and the extravagant claims of achievements in artificial intelligence [Schank, R. (1984) The Cognitive Computer: On Language, Learning and Artificial Intelligence. Addison-Wesley] together with rapidly increasing power/price ratio of microcomputers has led to much speculation about the development of intelligent computer-assisted learning. Intelligent computer-assisted learning systems consist of four modules: a natural language interface, a pedagogical module, a model of the student, and a knowledge base of the subject domain [Dede, C. (1986) Int. J. Man-Machine Studies 24, 329–353]. The three latter modules are still at very early experimental stages of development and pose formidable problems. The basis of current research in artificial intelligence is the physical symbol system hypothesis [Newell, A. and Simon, H. (1976) Communications of the ACM 19, 113–126. It is argued that no knowledge base of the subject domain language can be constructed on that basis [Winograd, T. (1987) Paper presented at the Humans, Animals, and Machines: Boundaries and Protections Conference, Stanford University]. Thus, inherent limitations of the physical symbol system hypothesis make (current) artificial intelligence techniques inappropriate for the development of intelligent CALL. However, teachers can use computers in language teaching in ways which are adapted to pedagogical goals. In this sense at least, intelligent computer-assisted language learning is possible.